In rotating machinery, it sometimes becomes necessary to trim the balance of one of the rotor elements after the machinery has been initially balanced for assembly and has been operating in service. Typically, the machinery must be disassembled, completely or partially, to permit rebalancing or trim balancing of the offending rotor element. With aircraft gas turbine engines, it is desirable to be able to quickly and easily trim balance the compressor rotor after an airfoil has suffered foreign object damage and the damaged blade or blades have been blended in without removal of the engine from an aircraft.
U.S. Pat. Nos. 4,803,893, 4,848,182 and 4,879,792 relate to the use of balance weights at selected locations to balance the rotor of a gas turbine engine.